[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040550
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Jul 4 2023

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is relocated to near 20W from
15N southward, and moving west near 10 kt. Scattered moderate
convection is seen from 08N to 14N between the Senegal-Guinea
Bissau coast and 23W.

A central Atlantic tropical wave is reanalyzed to be near 35W
from 17N southward, and moving west at 10 to 15 kt. Scattered
showers are evident from 04N to 10N between 34W and 38W.

A well-defined western Atlantic tropical wave is near 60W from
near Barbados southward to western Guyana, and moving west around
15 kt. Aided by abundant moisture, scattered showers and isolated
thunderstorms are occurring from northeastern Venezuela/northern
Guyana northward to the southern Leeward Islands, including
Trinidad and Tobago.

A western Caribbean tropical wave is near 82W from 18N southward
across Providencia and San Andres to near the Costa Rica-Panama
border, and moving west at 10 to 15 kt. Widely scattered showers
and isolated thunderstorms are noted north of Panama and Costa
Rica, and near Providencia and San Andres.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic along the Senegal coast near
Dakar and extends southwestward to near 12N23W. Other than the
convection described in the Tropical Waves section above, there is
no additional convection near the trough. An ITCZ continues from
12N23W to near 08N34W, then resumes westward from 06N38W to
06N51W. Widely scattered showers are seen up to 80 nm along either
side of the first ITCZ segment. Scattered moderate convection is
present near and up to 90 nm north of the second ITCZ segment.

The eastern end of the East Pacific monsoon trough near 11N is
causing scattered showers and thunderstorms in the Caribbean
waters near northwestern Colombia.

...GULF OF MEXICO...

A diurnal surface trough is triggering scattered showers and
isolated thunderstorms at the south-central Bay of Campeche.
Another surface trough across Florida is producing similar
conditions near the Florida Keys. Otherwise, a modest 1017 mb
high at the east-central Gulf and its related surface ridge
continue to dominate the region. Light to gentle winds and seas
of 1 to 2 ft are evident at the eastern Gulf, including the
Florida Straits. Gentle to moderate ESE to SE return flow with 2
to 4 ft seas prevail for the rest of the Gulf.

For the forecast, the modest surface ridge will prevail through
midweek, supporting mainly gentle to moderate return flow west of
90W and light to gentle winds east of 90W. Otherwise, moderate to
locally fresh winds will pulse nightly north and west of the
Yucatan peninsula into Wed as the diurnal trough develops and
moves offshore. Expect scattered thunderstorms across the SW Gulf
Tue through Wed.

...CARIBBEAN SEA...

An upper-level trough reaches north-northeastward from northern
Colombia through the Dominican Republic. Scattered showers and
thunderstorms are found near the trough axis over Haiti and the
Windward Passage, and also farther east across Puerto Rico, the
Virgin Islands and northern Leeward Islands. Refer to the Monsoon
Trough/ITCZ and Tropical Waves sections above for additional
convection in the Caribbean.

Tighter gradient between the Atlantic Ridge near the northwest
Bahamas and monsoon trough over northern Colombia is causing fresh
with locally strong easterly winds and seas of 6 to 8 ft at the
south-central basin. Moderate to fresh with locally strong E to
ESE trades associated with a tropical wave, along with 6 to 9 ft
seas exist at the eastern basin. Gentle to moderate ENE to ESE
winds and seas at 2 to 4 ft are noted near the ABC Islands and the
Cayman Islands/Jamaica and the Windward Passage/Cuba. Light to
gentle monsoonal winds and 2 to 4 ft seas are found north of
Panama and Costa Rica. Moderate to fresh easterly trades and seas
of 5 to 6 ft prevail elsewhere in the Caribbean Basin, including
the Gulf of Honduras.

For the forecast, fresh to strong winds will develop in the
central and eastern Caribbean through Wed night near and behind a
tropical wave that is moving across the Lesser Antilles tonight.
Expect squalls and scattered thunderstorms to accompany this
tropical wave through Tue night. Gentle to moderate trade winds
will prevail elsewhere through Sat, while fresh to strong trades
persist across the south-central basin.

...ATLANTIC OCEAN...

A Sahara Dust Layer (SAL) of modest thickness covers much of the
tropical Atlantic with its leading edge over Puerto Rico/Virgin
Islands and the Lesser Antilles. Hazy conditions with slightly
reduced visibilities are expected within this layer for the next
couple of days.

A robust upper-level trough stretches northward from the
Dominican Republic across an upper low near 27N66W to beyond
northeast of Bermuda. Widely scattered showers and isolated
thunderstorms are seen near these features from 22N to 30N between
60W and 74W. A surface trough near the east coast of Florida is
triggering similar conditions at southeastern Florida and the
northwest Bahamas. Refer to the Monsoon Trough/ITCZ and Tropical
Waves sections at the beginning for additional weather in the
Atlantic Basin.

The Atlantic Ridge extends southwestward from a 1029 mb Azores
High across 31N45W to near the northwest Bahamas. This feature is
supporting light to gentle winds and seas of 3 to 5 ft, north of
23N between 20W and the Georgia-Florida coast. Near the Canary
Islands, Moderate with locally fresh NNE trades and 5 to 7 ft seas
exist north of 22N between the northwest Africa coast and 20W.
Farther south near the Cabo Verde Islands, Gentle NW to NE winds
and seas at 4 to 5 ft are present from 13N to 22N between the
central Africa coast and 30W. To the west, moderate to fresh ENE
to ESE trades and 6 to 9 ft seas dominate from 06N to 23N between
30W and the Lesser Antilles. Gentle to moderate southerly and
westerly monsoonal winds with seas at 4 to 6 ft in moderate
southerly swell prevail for the remainder of the Atlantic Basin.

For the forecast west of 55W, the Atlantic Ridge will maintain a
weak pressure gradient and sustain light to gentle winds for the
waters north of 22N through midweek. South of 22N, moderate to
fresh winds will prevail through Thu, trailing behind an active
tropical wave moving through the Caribbean Sea.

$$

Forecaster Chan
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